tr7triumph.com

Posted: **07 Jan 2012 18:36**

On the fuel tank filler there is a black rubber hose from the top cap assembly to the tank. But, inside the rubber hose is a steel fuel pipe.
What is the purpose of the inside pipe? Why not just the rubber hose from the cap assembly to the tank?

The reason I ask is that I'm replacing my cap assembly with a custom system and I'm looking for a hose to fit. Can I use the original hose without the steel pipe?

**************
I couldn't repair my brakes, so I made my horn louder.
[img=left]http://i1239.photobucket.com/albums/ff504/tikvahmarketing/Forum_pic.jpg?t=1324940124[/img=left]

Posted: **07 Jan 2012 18:47**

Think the steel pipe may be part of the anti syphon device. Regards

Posted: **07 Jan 2012 21:25**

The gas goes through the steel pipe into the gas tank with there being no sealed connection to it. The rubber hose basically acts as a flexible seal to seal in vapours. I would have some reservations relying on just the rubber hose although it would work for a while but rubber deteriorates and would eventually leak I would think. A neoprene hose with steel spring reinforcement would be better.

http://www.gates.com/brochure.cfm?brochure=5076&location_id=5246

- - - - TR7 Spider - - - - - - - - 1978 Spitfire - - - - - - 1976 Spitfire - - 1988 Tercel 4X4 - Kali on Integra - 1991 Integra - - Yellow TCT

Posted: **08 Jan 2012 21:27**

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by supercass

Think the steel pipe may be part of the anti syphon device. Regards
<hr height="1" noshade id="quote"></blockquote id="quote">

.........and also to do with safety in the event of a crash. IIRC I read that the tank and its contects were designed to remain intact in a serious shunt. It enables the rear deck to move about but not rupture the filler pipe or tank.

Adam

TR7 V8 DHC Jaguar Solent Blue. 9.35cr Range Rover V8, Holley 390cfm, JWR Dual Port, 214 Cam, Lumention, Tubular Manifolds, S/S Single Pipe Exh, 3.08 Rear, 200lb Spax & PolyBushes all round, Anti- Dive, Strut-Top Roller Bearings, Capri Vented Discs & Calipers, Braided Hoses, 4 Speed Rear Cylinders, Uprated Master Cylinder & Servo, AT 14" 5 Spokes or Maestro Turbo 15" Alloys, Cruise Lights, S/S Heater Pipes, Replacement Fuel Tank. No Door Stickers. Mine since July 1986, V8 from 1991 courtesy of S&S V8 conversion and big brake kits.

Posted: **08 Jan 2012 21:36**

Hi,

The UK spec pipe also has a small pipe for brether.

I guess the US spec will be different as we dont have such things as carbon cannisters etc

Cheers John

LIVE LIFE A QUARTER OF A MILE AT A TIME!

1976 Speke FHC Beauty

1979 3.5 FHC(STATUS PENDING!!)

1982 2.0 DHC NOW A 4.6,ON THE ROAD NOW KICKING AR5E !!!!

Posted: **08 Jan 2012 23:16**

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by john 215

The UK spec pipe also has a small pipe for brether.

I guess the US spec will be different as we dont have such things as carbon cannisters etc
<hr height="1" noshade id="quote"></blockquote id="quote">

That's right. The fuel tank is vented to atmosphere (the gas cap is vented).

In N/A they didn't want these vapours into the air as the vapours and sunlight produced smog (on a clear day you couldn't see downtown LA). So they had a "sealed" system. A small metal tube in gas tank runs to outside where by a rubber hose goes to fuel separator which then goes to rubber hose to metal tube to engine bay to charcoal canister and then to intake. Crankcase vapours go to carbon canister as well which goes to intake. The gas cap is sealed. So by virtue of the intake vacuum the entire system is under vacuum (slight) not enough to prevent a carb fuel pump to pump gas to carbs. That is why if your system is working correctly (no leaks) there is a slight whoosh of air as you open the gas cap as air rushes in. If the system leaks you won't achieve the maximum vacuum in intake. The system doesn't cause any power loss as canister(s) don't weigh that much. They do take up room in the engine bay though.

Also to eliminate gas vapours in the States when you fill up you also have a spring loaded cover on the fill nozzle that has to be compressed before the fuel flow can be started. Here in Canada we just have a cover that kind of stops the vapours from escaping (doesn't really just a concession to the environmentalists who don't know any better).

- - - - TR7 Spider - - - - - - - - 1978 Spitfire - - - - - - 1976 Spitfire - - 1988 Tercel 4X4 - Kali on Integra - 1991 Integra - - Yellow TCT

Posted: **09 Jan 2012 02:32**

Still can't see down town LA on a clear day.
Guess it ain't working

Don
"No More Cars For You"
71 TR6- Perpetual remodel
80 TR7 V8 Kick in the pants

Posted: **09 Jan 2012 14:12**

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by DNK

Still can't see down town LA on a clear day.
Guess it ain't working
<hr height="1" noshade id="quote"></blockquote id="quote">

You could when I went through in June but maybe it was just one of those days.[8D]

- - - - TR7 Spider - - - - - - - - 1978 Spitfire - - - - - - 1976 Spitfire - - 1988 Tercel 4X4 - Kali on Integra - 1991 Integra - - Yellow TCT

Posted: **09 Jan 2012 15:50**

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by FI Spyder

... You could when I went through in June ... <hr height="1" noshade id="quote"></blockquote id="quote">
So you clearly spoilt it [:p]

<center>

1980 TR7 DHC (my first car, now restored and back on the road)
1981 TR7 FHC Sprint (better known as 't Kreng)
[url="http://www.tr7beans.blogspot.com/"]My Weblog[/url]</center>

Posted: **09 Jan 2012 17:38**

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by FI Spyder I would have some reservations relying on just the rubber hose although it would work for a while but rubber deteriorates and would eventually leak I would think. A neoprene hose with steel spring reinforcement would be better.
<hr height="1" noshade id="quote"></blockquote id="quote">

The MGB had an opening through the trunk floor that a large rubber hose connect it to the filler piece. No worries there.

-Tim
http://www.morSpeedPerformance.com

Posted: **09 Jan 2012 17:47**

Tim,
My 63 MGB has a metal pipe in exactly the same shape as your rubber one with short rubber connections on both ends. I think it's one of the clunkier design decisions made by the folks at Abingdon.
Jim

Posted: **09 Jan 2012 21:52**

Oh, I thought you meant from any where.

Don
"No More Cars For You"
71 TR6- Perpetual remodel
80 TR7 V8 Kick in the pants

Posted: **10 Jan 2012 12:26**

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by jbsjim

Tim,
My 63 MGB has a metal pipe in exactly the same shape as your rubber one with short rubber connections on both ends. I think it's one of the clunkier design decisions made by the folks at Abingdon.
<hr height="1" noshade id="quote"></blockquote id="quote">

Mine has the same, but I've seen the all rubber ones, that's why I posted this pic.

-Tim
http://www.morSpeedPerformance.com

Posted: **10 Jan 2012 16:04**

Seems rather exposed in the trunk, exposed to things in the trunk ramming into it but then I don't suppose to many MGB owners use their cars to haul cement patio blocks or packages of hardwood flooring like I do in my TR7.

- - - - TR7 Spider - - - - - - - - 1978 Spitfire - - - - - - 1976 Spitfire - - 1988 Tercel 4X4 - Kali on Integra - 1991 Integra - - Yellow TCT

Posted: **10 Jan 2012 16:41**

FI, back when I was a lad I reroofed my brother's garage in Berkeley. My 67 B hauled all of the roofing materials from nearby Oakland. Talk about a low rider!
Jim

tr7triumph.com

Fuel Tank Filler

Fuel Tank Filler